The World Heart Federation has joined a global call to action for governments to update their national climate commitments under the Paris Agreement, in line with their fair share of limiting warming to 1.5°C. The call comes ahead of the UN climate conference (COP26) in Glasgow, UK as more than 300 organizations representing at least 45 million nurses, doctors and health professionals worldwide – about three quarters of the global health workforce – signed an open letter to the 197 government leaders and national delegations ahead of COP26, warning that the climate crisis is the single biggest health threat facing humanity, and calling on world leaders to deliver on climate action.